Who can hit the mark?

Note: Everything that is written in GREEN must be in your notebook from this point forward. 

Accuracy is correctness. For example, if a coin has a mass of 10.0701 grams, these would all be accurate masses: 10 g, 10.1g, 10.07 g, 10.070 g But an inaccurate mass would be 25 grams. Precision is exactness. Precision comes from the type of measuring tool you use.

Which shooter is more precise? a. c. b. d.

Which shooter is more accurate, but not precise? d.

They would be accurate, but not sufficiently precise. https://youtu.be/0KLy- NnTD2o?t=2m59s http://www.usatoday.com/st ory/sports/olympics/rio- 2016/2016/08/11/simone- manuel-abbey-weitzeil- swimming-womens-100- freestyle-final-result/88595514/ What if both stopwatches read 51 seconds? They would be accurate, but not sufficiently precise.

So what does this have to do with Significant Figures? Significant Figures are used to measure the degree of precision in a measurement.

In science, for a measurement to be both accurate and precise, it must include all KNOWN digits plus an estimated digit. The correctly precise measurement for the ruler on the top is 1.5 inches. However, the correctly precise measurement for the ruler on the bottom is 1.48 inches.

What is the volume of each graduated cylinder?

Rules for counting Sig Figs- 1. ALL non-zero numbers are significant. How many sig figs in this number? 1,989 4 Sig Figs

Rules for counting Sig Figs- 2. ALL sandwiched zeros are significant. How many sig figs in this number? 2,001,248 7 sig Figs

Rules for counting Sig Figs- 3. ALL trailing zeros AFTER a decimal are significant. How many sig figs in this number? 6.00 3

Rules for counting Sig Figs- 4. If there is NO DECIMAL, the trailing zeros are NOT significant. How many sig figs in this number? 600 1

Rules for counting Sig Figs- 5. ALL LEADING zeros are NOT significant. How many sig figs in this number? 0.0075 2

How many sig figs are in this number: 273.5200? Ask yourself: Is the decimal point present or absent?

“If it’s bigger than 1 with a decimal point, they’re alllll sig figs!” Answer: Present “If it’s bigger than 1 with a decimal point, they’re alllll sig figs!” 273.5200 7 S.F.

Identifying Significant Figures Practice Write the # and # of SF 500 301 2,060 12.06 2,060.0 14,000 0.0017 1.4000 28.03 0.087

Identifying Significant Figures Practice Write the # and # of SF 500 301 2,060 12.06 2,060.0 14,000 0.0017 1.4000 28.03 0.087 1 3 5 2 4

Using Sig Figs in Calculations Addition and Subtraction When you + or – measurements, the answer MUST have the same number of digits to the right of the decimal as the original value that has the fewest number of digits to the right of the decimal. …let me show you

Adding & Subtracting with Sig Figs But according to Sig Fig +/- Rules, the answer has to have the SAME # of digits to the RIGHT of the decimal. So the answer is… 258.3 kg 257.11 kg 253 kg + 768.41 kg 768 kg

Write the answer and # of SF Adding & Subtracting Write the answer and # of SF 500 + 1.7 0.199 + 20 66.89 - 6 50.26 – 10.26 28.03 + 12.5

Write the # and # of SF Adding & Subtracting with Sig Figs =502 =20 500 + 1.7 0.199 + 20 66.89 - 6 50.26 – 10.26 28.03 + 12.5 =502 =20 =60 =40.00 =40.5

Practice Measuring 4.5cm 4.77cm 3.0cm

Multiplying and Dividing with Sig Figs When you multiply or divide, your answer must have the same number of significant figures as the measurement with the fewest significant figures.

Multiplying and Dividing with Sig Figs 24m x 3.26m 1.23g x 2.0g 4.84m ÷ 2.4s 168m ÷ 58s 120km x 0.10km

Multiplying and Dividing with Sig Figs 24m x 3.26m 1.23g x 2.0g 4.84m ÷ 2.4s 168m ÷ 58s 120km x 0.10km 78m2 2.5g2 2.0m/s 2.9m/s 1.2km2